Shadow Shaman
* Sniper can easily destroy 
Mass Serpent Wards from long range.
Medusa
* Sniper can outrange both Medusa's arrows and Stone Gaze, allowing him to focus her down during a teamfight.
Additional:
* Medusa is a fairly immobile hero that deals damage around her with 
Split Shot. Sniper should outrange her and should stay out of harm's way from Split Shot.
* More importantly, Sniper should have enough attack range to fire at Medusa during her 
Stone Gaze without turning to stone, so the ultimate is mostly wasted against him.
Shadow Shaman
* 
Arc Warden with his Magnetic Field will protect allies from Mass Serpent Ward.
Medusa
* He can use either his own or his double's 
Flux to bypass the spellblock from Linken's Sphere, using the leftover Flux + 
Spark Wraith to slow Medusa's already low move speed to a crawl.
* Arc Warden has a farming advantage with double 
Hand of Midas, and can generally bully Medusa with other items that benefit from duplication.
Shadow Shaman
* Support heroes with low mobility can be slowed further by Incapacitating Bite, and swarmed by Spiderlings for an easy kill: 
Shadow Shaman, 
Visage, 
Dazzle, 
Rubick, 
Lich.
Medusa
* Webbed areas can be used to hit and run, covering distance hastily weakening her on the way and initiating ganks.
* Even though Medusa can hunt down Spiderlings easily when given enough range, 
Silken Bola will cause her attacks to miss and get her swarmed in no time.
* Medusa usually does not build a Black King Bar to benefit from 
Mana Shield fully while Broodmother can fit a 
Diffusal Blade to burn away all of Medusa's mana.
Additional:
* 
Spin Web will allow Broodmother to pick her own fights and sometimes slip away to ambush Medusa.
* Though Medusa's Split Shot and Mystic Snake can help Medusa deal with Broodmother's spiderlings, Broodmother will create too much of them for her to handle, allowing her to outnumber Medusa's targets from Split Shot and shield her team in process.
Shadow Shaman
* 
Nyx Assassin, 
Bounty Hunter and 
Slark can all sneak up and kill Shadow Shaman, Nyx being particularly deadly. Shadow Shaman must watch out for Slark carefully, as he can break either (but not both unless he makes a mistake) of Shadow Shaman's disables, with 
Dark Pact and leap out of a serpent ward ring. These heroes, however, rely heavily on escape and are themselves not very durable and none of them can survive a full lockdown with Mass Serpent Ward. Having Sentry Wards can turn Shadow Shaman from prey to predator.
Medusa
* 
Vendetta burns a significant amount of mana on hit, and the damage from the ability drains Medusa's mana pool even further.
* Due to the passive nature of Mystic Snake and Split Shot, it can possibly proc Nyx's 
Spiked Carapace if he's within range of Medusa's abilities and isn't invisible.
* Medusa lacks single target damage, making Nyx with 
Aghanim's Scepter extremely hard to deal with if Medusa is the team's main damage source.
Additional:
* With her passive Split Shot, Medusa can be easily interrupted by Spiked Carapace during combat, especially during her precious Stone Gaze.
* Mana Burn quickly destroys Mana Shield, especially if Medusa only increases her mana pool by bolstering intelligence (which has the added bonus of increasing Mana Burn's damage).
* Uncontrollable damage from 
Mystic Snake and Split Shot can trigger Spiked Carapace.
* 
Medusa lacks single target damage, making a Burrowed Nyx Assassin hard to kill.
Shadow Shaman
* With 4 active abilities, Shadow Shaman is weak against silencing foes such as 
Silencer, 
Drow Ranger and 
Death Prophet.
Medusa
* Silencer burns easily through her effective HP from Mana Shield, by taking away her intelligence.
* 
Arcane Curse punishes her repeatedly casting Mystic Snake to keep her mana pool high. He can force her to use 
Manta Style before he has cast 
Global Silence and Medusa usually does not want to build 
Black King Bar.
Shadow Shaman
* Nyx Assassin, Bounty Hunter and Slark can all sneak up and kill Shadow Shaman, Nyx being particularly deadly. Shadow Shaman must watch out for Slark carefully, as he can break either (but not both unless he makes a mistake) of Shadow Shaman's disables, with Dark Pact and leap out of a serpent ward ring. These heroes, however, rely heavily on escape and are themselves not very durable and none of them can survive a full lockdown with Mass Serpent Ward. Having Sentry Wards can turn Shadow Shaman from prey to predator.
Medusa
* Medusa is especially vulnerable to 
Essence Shift, as both strength and intelligence contribute to her effective HP, while agility contributes to her damage.
* Dark Pact when timed right can be used to dispel Stone Gaze right after it petrifies Slark, allowing him to keep attacking Medusa throughout the duration.
Additional:
* Medusa cannot chase Slark in any way and has no disable beyond her ultimate, making her unable to stop him getting away and regenerating before coming back to finish her off.
* Essence Shift particularly removes 1 intelligence point per hit, thus lowering Medusa's mana pool's cap and leaving her much more vulnerable in prolonged fights.
Medusa
* Ursa's status resistance from 
Enrage reduces duration of Medusa's Stone Gaze.
* Ursa can stack damage with 
Fury Swipes easily against her Mana Shield in a prolonged team match.
Additional:
* Medusa's tankiness doesn't help her very much against Fury Swipes in long teamfights.
* With no escape mechanism and a slow movement speed, getting jumped on by Ursa usually spells a quick end for Medusa in the early game.
Shadow Shaman
* 
Reincarnation allows Wraith King to survive Shadow Shaman's initial chain of disables and Serpent Ward attacks.
* Short cooldown of 
Wraithfire Blast is ideal for interrupting Shackles.
Medusa
* With 
Static Link, Razor can effectively make Medusa useless in teamfights by reducing her main damage output. It can, however, be blocked by a 
Linken's Sphere.
* 
Plasma Field allows Razor to get on top of Medusa, slowing her already slow movement speed to a mere crawl.
* 
Eye of the Storm capitilizes on Medusa's low armor and causes her to be very vulnerable, even through Mana Shield.
Shadow Shaman
* 
Ether Shock is a great farming ability as a handy short-cooldown nuke.
* 
Hex and 
Shackles gives Rubick extra lockdown potential in ganks and teamfights.
* Mass Serpent Ward, should Rubick steal, serves as a powerful source for teamfighting, pushing, and acquring Roshan.
* 
Arcane Supremacy allows Rubick to cast Hex and Shackles at a further distance, which keeps Rubick at a safer position compared to Shadow Shaman.
* Rubick can interrupt Shackles by casting 
Telekinesis.
Additional:
* All abilities from Shadow Shaman can very vulnearble steal from 
Spell Steal.
* Rubick can interrupt Shackles by casting Telekinesis.
Shadow Shaman
* As a caster, 
Anti-Mage's 
Mana Break and 
Mana Void are highly effective against him.
Medusa
* Anti-Mage easily destroys Mana Shield with Mana Break, especially once he has Manta Style.
* Anti-Mage effectively avoids Stone Gaze with Blink, and can reinitiate after its duration is over.
Additional:
* Mana Break burns Medusa's mana easily, especially when coupled with a Manta Style.
* Can easily initiate on Medusa with 
Blink, burning her mana or forcing her to use Stone Gaze.
* Mana Void is effective against Medusa's big mana pool and mana usage, presenting a huge hazard to Medusa's allies around her since her Mana Shield still gives her some protection if she has mana.
Shadow Shaman
* Heroes with abilities or items that can silence or disable Anti-Mage for long periods of time will prevent him from Blinking away: 
Lion, Silencer, Shadow Shaman, 
Grimstroke, 
Witch Doctor, 
Riki, 
Faceless Void, 
Skywrath Mage, 
Puck.
Medusa
* Medusa lacks mobility or escape mechanisms. 
Earth Spike and 
Hex can neutralize her strong damage potential and allow for Lion's team to focus her down.
* 
Mana Drain is a perfect ability to weaken Medusa's durability as it can quickly drain her Mana Shield, making her far less tanky. Mana Drain can also be used to restore mana of Lion's allies, which can nullify the mana steal from Mystic Snake.
* Mana Drain, along with Hex, destroy illusions instantly, which may be extremely helpfull and efficient against core builders of Manta Style, like Medusa herself.
Shadow Shaman
* Dragon Knight can simply tank and destroy all Shadow Shaman's Serpent Wards.
Shadow Shaman
* Mirana can disturb Shadow Shaman's channeling even if he is under the effect of invisibility thanks to 
Sacred Arrow.
* Mirana armed with an Aghanim's Scepter is known to be able to quickly burst down heroes - especially supports. Together with 
Ethereal Blade the bullying towards Shadow Shaman can continue for the whole match.
Medusa
* Phantom Lancer with Diffusal Blade will very quickly burn Medusa's mana, making Mana Shield significantly less effective.
* 
Doppelganger's 1 second invulnerability can be used to dodge Medusa's petrification from Stone Gaze, as well as Mystic Snake.
* Phantom Lancer's illusions outnumber Medusa's targets from Split Shot, likely shielding his team in the process.
Shadow Shaman
* 
Waveform allows Morphling to escape from Mass Serpent Ward
* Morphling can interrupt Shadow Shaman while he is shackling an ally with 
Adaptive Strike (Strength).
* With Ethereal Blade Morphling can quickly burst him down before he even has a chance to react.
Shadow Shaman
* By simply using Aphotic Shield, Abaddon can easily save his allies from heroes that apply long disables, such as Lion or Shadow Shaman.
Shadow Shaman
* 
Omniknight can dispel Hex or Shackles with 
Heavenly Grace. He can also heal teammates who you disabled. The same goes for 
Abaddon's 
Aphotic Shield.
Shadow Shaman
* 
Pudge, 
Legion Commander and 
Axe will make the match a living hell for Shadow Shaman, since they are known for surprise attacks from the fog and quickly killing low HP heroes. They can also interrupt Shadow Shaman's channeling, Legion being especially problematic, as she can use 
Press the Attack on an ally who is hexed as well.
Medusa
* Axe can take advantage of Medusa's awfully low HP to insta-kill her with 
Culling Blade, making it extremely difficult for her to farm for items to compensate for the lack of strength during early and mid-game while Axe is continuously harassing around.
Medusa
* Mana Shield reduces the effectiveness of Counter Helix.
* Stone Gaze makes it very difficult for Axe to initiate on Medusa and her allies.
Shadow Shaman
* Lone Druid's early game is good against slow, squishy supports since his bear is very strong early game and an Entangling Claws proc almost always guarantees a kill: 
Ancient Apparition, 
Crystal Maiden, Shadow Shaman, etc.
Shadow Shaman
* Nyx Assassin, Bounty Hunter and Slark can all sneak up and kill Shadow Shaman, Nyx being particularly deadly. Shadow Shaman must watch out for Slark carefully, as he can break either (but not both unless he makes a mistake) of Shadow Shaman's disables, with Dark Pact and leap out of a serpent ward ring. These heroes, however, rely heavily on escape and are themselves not very durable and none of them can survive a full lockdown with Mass Serpent Ward. Having Sentry Wards can turn Shadow Shaman from prey to predator.
Medusa
* Heroes who take a long time to become strong are in for a rough mid game, such as 
Outworld Destroyer, 
Magnus, Medusa, and Anti-Mage.
Shadow Shaman
* With 4 active abilities, Shadow Shaman is weak against silencing foes such as Silencer, Drow Ranger and Death Prophet.
Medusa
* Heroes that build Diffusal Blade or can fit it well into their item build will also make Medusa much less tanky: Riki, 
Naga Siren, 
Terrorblade, 
Juggernaut, 
Spectre, Slark.
Medusa
* Other heroes who has armor and slow debuffs won't allow Medusa to disengage from combat: 
Tidehunter, 
Bristleback, 
Slardar.
Shadow Shaman
* Heroes with channeling spells are very easy targets for Jakiro's abilities: Crystal Maiden, 
Dawnbreaker, 
Enigma, Pudge, 
Shadow Fiend, Shadow Shaman, 
Warlock.
Shadow Shaman
* With 4 active abilities, Shadow Shaman is weak against silencing foes such as Silencer, Drow Ranger and Death Prophet.
Shadow Shaman
* Heroes that have a channeled ability that can be interrupted by Meat Hook: Shadow Shaman, Witch Doctor, Enigma, 
Bane.
Medusa
* Heroes with extremely slow movement speed will cripple against Solar Bind: Medusa, 
Viper
Additional:
* 
Will-O-Wisp will keep Medusa busy after she got hit by 
Blinding Light.
Shadow Shaman
* Single-target disablers will have difficulty locking down a Chaos Knight with Phantasm active: Bane, 
Beastmaster, 
Bloodseeker, 
Clockwerk, 
Doom, Shadow Shaman.
Medusa
* Other heroes who has armor and slow debuffs won't allow Medusa to disengage from combat: Tidehunter, Bristleback, Slardar.
Medusa
* Fiend's Grip provides mana drain, which can heavily damage Mana Shield and prevent Medusa from using Stone Gaze.
* Even if she does use Stone Gaze, Nightmare can buy enough time to protect allies and reset the fight.
Additional:
* 
Fiend's Grip leaves Medusa defenseless, since not only does it deal damage, it also drains mana.
Shadow Shaman
* Hex abilities can cancel the channelling of Fiend's Grip : Lion, Shadow Shaman, Dazzle from 
Aghanim's Shard with upgraded 
Poison Touch.
Medusa
* E.M.P. allows Invoker to burn Medusa's mana to weaken Mana Shield.
* Medusa's lack of mobility makes her easy to kite with Invoker's spells.
Additional:
* 
E.M.P. is a large mana burn nuke which can hit Medusa's Mana shield with enough damage to lose even more mana.
* 
Deafening Blast disarms Medusa's ability to deal pseudo-AOE damage during teamfights.
* 
Cold Snap allows the opposing team to repeatedly stun Medusa in short succession, preventing her from successfully casting her ultimate due to its long cast time.
Shadow Shaman
* Heroes with long lockdowns: Shadow Shaman, Legion Commander.
Medusa
* 
Bulwark can make each of Medusa's attacks target him instead, reducing Medusa's contribution on team fights.
* 
Spear of Mars stuns Medusa and also pushes her away from teamfights, taking advantage of Medusa's low mobility.
* 
Arena Of Blood blocks Medusa's attacks from outside the arena.
Medusa
* Medusa's Stone Gaze forces Mars to choose between getting petrified, or turning his vulnerable back on Medusa.
Shadow Shaman
* Spectre's entire ability set is designed to get to and destroy heroes that stay in the backlines, both carries (like the aforementioned Drow Ranger and 
Sniper) and supports (like Dazzle and Shadow Shaman).
Medusa
* Heroes that build Diffusal Blade or can fit it well into their item build will also make Medusa much less tanky: Riki, Naga Siren, Terrorblade, Juggernaut, Spectre, Slark.
Shadow Shaman
* Hex can be used immediately to destroy Spectre's illusion when she 
Haunts.
* Shadow Shaman can use Shackles to lock down Spectre for his team.
* Shadow Shaman's Mass Serpent Ward and Ether Shock help him push lanes and end the game early before Spectre can come online and take over the late game.
Shadow Shaman
* Shackles prevents Chen from acting, and damages him while healing Shadow Shaman, also allowing Shadow Shaman's allies to kill him faster. Aghanim's Shard upgraded Shackles can also summon four more Mass Serpent Wards to attack Chen while he is disabled. And to make things worse, Chen has no way to cancel Shackles on his own, and must rely on outside from {U:Centaur Conqueror} or {U:Mud Golem} under his control.
* Ether Shock and Mass Serpent Ward can often not only kill Chen's allies before he can save them with 
Hand of God, but they can also be used to destroy Chen's creeps easily thanks to their high damage and area-of-effect.
* Hex will prevent Chen from any attempt to save himself or his allies with Hand of God.
Additional:
* Shackles prevents Chen from acting, and damages him while healing Shadow Shaman, also allowing Shadow Shaman's allies to kill him faster. Aghanim's Shard upgraded Shackles can also summon four more Mass Serpent Wards to attack Chen while he is disabled. And to make things worse, Chen has no way to cancel Shackles on his own, and must rely on {U:Centaur Conqueror} or {U:Mud Golem} creeps under his control to be able to do so.
* Ether Shock and Mass Serpent Ward can often not only kill Chen's allies before he can save them with Hand of God, but they can also be used to destroy Chen's creeps easily thanks to their high damage and area-of-effect.
* Hex will prevent Chen from any attempt to save himself or his allies with Hand of God.
Medusa
* Medusa's Split Shot can easily kill Chen's creeps.
* Mystic Snake can quickly kill Chen's creeps and deal intense damage for every killed creep while also draining their mana with each bounce. Aghanim's Scepter upgraded Mystic Snake can also disable both, Chen and his creeps upon impact.
* Mana Shield will make it impossible for Chen to burst down Medusa.
* Stone Gaze can disable Chen from using Hand of God to save himself or his allies.
Shadow Shaman
* Shackles and Hex can both be used on Muerta while in 
Pierce the Veil, potentially wasting it until she gets Black King Bar.
* Ether Shock and Shackles can deal high damage to Muerta while she is affected by Pierce the Veil.
* However, Mass Serpent Ward cannot hurt Muerta while Pierce the Veil is active.
Medusa
* Any long duration disables that can pierce through both, Pierce The Veil and Black King Bar are devastating against Muerta: Enigma's 
Black Hole, Dawnbreaker's 
Solar Guardian, Axe's 
Berserker's Call, Naga Siren's Aghanim's Scepter upgraded 
Ensnare and 
Reel In from Aghanim's Scepter, 
Jakiro's Aghanim's Scepter upgraded 
Macropyre, Bane's Fiend's Grip, Pudge's 
Dismember, 
Batrider's 
Flaming Lasso, Beastmaster's 
Primal Roar, Grimstroke's 
Soulbind, Medusa's Stone Gaze, Magnus's 
Reverse Polarity.
Shadow Shaman
* Heroes with break can disable Untouchable for a while: Doom and 
Shadow Demon (via Aghanim's Scepter), Viper, Shadow Shaman with Hex Breaks talent.
Medusa
* Enchantress often has a small army of neutral creeps, allowing Medusa to hit her with a later bounce of her Mystic Snake.
Shadow Shaman
* Heroes who can clear the waves of Enigma's Eidolons: 
Lina, 
Luna, Dawnbreaker, Jakiro, Shadow Shaman, Death Prophet, 
Keeper of the Light, 
Invoker, 
Leshrac, Puck.
Medusa
* Medusa's Split Shot can make quick work of Enigma's Eidolons and take advantage of their considerable bounty.
* Medusa can also kill Eidolons with her Mystic Snake that can also greatly damage Enigma and drain some of his mana.
* If Medusa activates Stone Gaze at the start of a fight, it can make initiating and landing an effective Black Hole exceedingly difficult, because Stone Gaze can cancel Enigma's Black Hole even through spell immunity, which can discourage Enigma from even trying to initiate with Black Hole.
Additional:
* Medusa's Split Shot can make quick work of Enigma's Eidolons and take advantage of their considerable bounty.
* If Medusa activates Stone Gaze at the start of a fight, it can make initiating — and landing an effective Black Hole exceedingly difficult. Stone Gaze can cancel Enigma's Black Hole even through spell immunity, which can discourage Enigma from initiating with Black Hole.
Shadow Shaman
* Sven is very vulnerable to chain stun such as Lion, Shadow Shaman or Magnus.
Medusa
* Stone Gaze allows Medusa to easily kite and kill Sven.
* Mana Shield negates much of Sven's burst damage.
Additional:
* Mana Shield makes it very hard for Sven to burst her within Storm Hammer's stun duration.
* Stone Gaze makes it very difficult for Sven to fight Medusa at any stage of the game.
* Mystic Snake can slow Sven down enough for allies to capitalize on his commitment in a fight.
Shadow Shaman
* Heroes that are squishy by nature are an easy target for Spirit Breaker: Sniper, Drow Ranger, Shadow Shaman
Shadow Shaman
* Can easily interrupt and disable Spirit Breaker with hex if being charged.
Medusa
* If Medusa activates Stone Gaze before Spirit Breaker reaches her with Charge of Darkness, the charge will inevitably fail.
* Medusa has three ways to counter Spirit Breaker's Charge of Darkness: Stone Gaze can disable Spirit Breaker's Charge of Darkness if he faces Medusa directly. Aghanim's Scepter upgraded Mystic Snake can disable Spirit Breaker and cancel his Charge of Darkness if it hits him. And 
Cold Blooded provided by Aghanim's Shard that can cast a single-targeted Mystic Snake at Spirit Breaker if he uses Charge of Darkness on her.
* Mana Shield and overall tankiness allows Medusa to easily survive Spirit Breaker's initiation. And to make things worse, Spirit Breaker is not a common Diffusal Blade nor 
Disperser wielder to counter this problem at all.
* Overall, any attempt for Spirit Breaker to gank and kill Medusa will hurt him more than the other way around.
Shadow Shaman
* Any hero who can counter-initiate in anticipation without getting caught in Reverse Polarity: 
Sven, Omniknight, Enigma, Luna, Naga Siren, 
Mars, Jakiro, 
Venomancer, 
Elder Titan, Faceless Void, Rubick, Keeper of the Light, 
Pugna, Invoker, Spectre, 
Alchemist, 
Treant Protector, Lina, 
Oracle, 
Zeus, Shadow Shaman, 
Phoenix, 
Razor, 
Huskar, Batrider, 
Kunkka, Tidehunter, 
Wraith King, 
Sand King, Medusa, Dawnbreaker.
Medusa
* Any hero who can counter-initiate in anticipation without getting caught in Reverse Polarity: Sven, Omniknight, Enigma, Luna, Naga Siren, Mars, Jakiro, Venomancer, Elder Titan, Faceless Void, Rubick, Keeper of the Light, Pugna, Invoker, Spectre, Alchemist, Treant Protector, Lina, Oracle, Zeus, Shadow Shaman, Phoenix, Razor, Huskar, Batrider, Kunkka, Tidehunter, Wraith King, Sand King, Medusa, Dawnbreaker.
Shadow Shaman
* Heroes with both illusions and summons, for Io has nothing to deal with multiple enemies at once outside from Spirits's weak area-of-effect: Beastmaster, 
Broodmother, 
Chaos Knight, 
Lycan, Naga Siren, 
Nature's Prophet, 
Phantom Lancer, Shadow Shaman, Terrorblade, Visage, Warlock, Wraith King.
Medusa
* Heroes that are hard to gank: Axe, Death Prophet, Phantom Lancer, Slark, 
Centaur Warrunner, Bristleback, Medusa, Mars.
Shadow Shaman
* Heroes with illusions and summons can be hard for Phantom Assassin to deal with, as she lacks any AoE abilities to deal with them without items: Broodmother, Phantom Lancer, Chaos Knight, Lycan, Naga Siren, Shadow Shaman, Visage, Nature's Prophet, Terrorblade, Warlock, Wraith King.
Medusa
* Heroes with disables that ignore spell immunity will render Phantom Assassin completely useless in teamfights throughout the game: Axe, Enigma, 
Vengeful Spirit, Doom, Bane, Beastmaster, Pudge, Medusa, Warlock.
Medusa
* Doom does not disable Mana Shield. As such, Doom's damage is largely mitigated by her mana shield. Additionally, Medusa is not reliant on her abilities to be effective during a teamfight, making Medusa an unproductive hero to target.
* Medusa is an ideal Linken's Sphere carrier. Should one be purchased, and without any additional disables, Doom may find that few opportunities exist to effectively lockdown, disable, and kill Medusa.
Medusa
* Split Shot will keep attacking Pangolier even when he is rolling around.
* Stone Gaze stuns Pangolier during Rolling Thunder, or forces him to roll away.
Shadow Shaman
* Shackles and Mass Serpent Ward instantly destroy 
Refraction
Shadow Shaman
* Shadow Shaman's Mass Serpent Ward together with Ether Shock can easily kill lots of Treants if played defensively.
* Hex and Shackles can disrupt Nature's Prophet's escape attempts with Teleportation.
Additional:
* Mass Serpent Ward can kill lots of treants if played defensively.
* Mass Serpent Ward, Hex, and Shackles can catch and kill a Nature's Prophet trying to use Teleportation.
Medusa
* Her Mana Shield is too tough for Lycan to break.
* Mystic Snake can hit for a massive damage once it spread between his summons.
Additional:
* Can be easily petrified despite his speed.
* Summoned wolves will be targeted by Split Shot or Mystic Snake
Medusa
* Mana Shield can tank most of the damage from Reaper's Scythe; with sufficient mana, the kill threshold drops significantly.
* Necrophos has a movement speed equal to Medusa, and is easy to chase down with a slowing item in Medusa's inventory.
Shadow Shaman
* Hex greatly reduces Timbersaw's mobility.
* The stun and damage over time from Shackles mitigates Reactive Armor's HP and armor regen.
Shadow Shaman
* Shadow Shaman has many disables to lock down Queen of Pain, preventing her from Blinking away, even through Linken's Sphere or her spell block talent.
* Mass Serpent Ward can tear through Queen of Pain's low health pool once she's locked down by Hex & Shackles.
Shadow Shaman
* Shadow Shaman's long disables are effective at kiting and wasting the duration of Battle Trance.
* Mass Serpent Ward are especially effective against Troll Warlord during Battle Trance, as trapping him inside them during the duration is effectively another hard disable, as Troll cannot attack the wards or use Phase Boots to escape.
Shadow Shaman
* Hex's instant cast time will force Brewmaster into the awkward situation of needing some form of spell immunity or block to prevent being immediately hex upon blinking in, or wait until Shaman has used all his crowd control before entering a fight.
* Brewmaster also has no defense against Shadow Shaman lockdowns.
Shadow Shaman
* Shadow Shaman's many disables can lock down Weaver. Even with Linken's Sphere, Weaver might not be able to escape should Shadow Shaman uses Shackles quickly enough following Hex.
* Mass Serpent Wards can make short work of Weaver once he is locked down.
Medusa
* Split Shot can destroy Tombstone Zombies and Tombstone itself while still damaging heroes.
Medusa
* Mana Shield makes it very difficult for Bloodseeker to gain his Thirst bonuses.
* Rupture rarely kills Medusa through Mana Shield.
Medusa
* Lifestealer's low mobility makes him easy to kite.
* Stone Gaze pierces 
Rage, wasting its cooldown and making Lifestealer unable to fight.
Shadow Shaman
* Pudge, Legion Commander and Axe will make the match a living hell for Shadow Shaman, since they are known for surprise attacks from the fog and quickly killing low HP heroes. They can also interrupt Shadow Shaman's channeling, Legion being especially problematic, as she can use Press the Attack on an ally who is hexed as well.
Shadow Shaman
* Heroes with long or multiple disables will prevent Legion Commander from winning Duels: Shadow Shaman, Lion
Medusa
* Mana Shield makes Medusa very hard to take down in Duels.
* Stone Gaze stops Legion Commander from Dueling altogether, regardless of who she targets.
Medusa
* Heroes with Linken's Sphere as core item: 
Weaver, 
Morphling, Medusa.
Medusa
* Heroes with a lot of burst damage, especially those who rely on casting spells: Lina, Zeus.
Shadow Shaman
* In general, squishy heroes that rely on escape often struggle against the amount of disables Shadow Shaman can bring. 
Queen of Pain, Anti-Mage and 
Storm Spirit are among these.
Shadow Shaman
* Luna's high magical damage burst from 
Lucent Beam and 
Eclipse can take advantage of Shadow Shaman's low health and strength gain.
* Without Black King Bar, Luna's Lucent Beam and 0.25 Eclipse Mini-stun talent for Eclipse can be used to disable Shadow Shaman while he is channeling Shackles.
* Aghanim's Scepter upgraded Eclipse combined with 0.25 Eclipse Mini-stun can repetively stun Shadow Shaman, and can even discourage him from even trying to use Shackles.
* Luna is a natural Black King Bar wielder, and almost none of Shadow Shaman's spells can bypass spell immunity, except for Mass Serpent Ward.
* Bear in mind, however, that if Shadow Shaman gets a jump on Luna first, he will be able to use Hex to disable Luna and burst her down before she can use Black King Bar, Lucent Beam or Eclipse. In addition, 
Moon Glaives cannot bounce on Mass Serpent Wards at all.
Additional:
* Luna's high magical damage burst from Lucent Beam and Eclipse can take advantage of Shadow Shaman's low health and strength gain.
* Without Black King Bar, Luna's Lucent Beam and 0.25 Eclipse Mini-stun talent for Eclipse can be used to disable Shadow Shaman while he is channeling Shackles.
* Aghanim's Scepter upgraded Eclipse combined with 0.25 Eclipse Mini-stun can repetitively stun Shadow Shaman, and can even discourage him from even trying to use Shackles.
* Luna is a natural Black King Bar wielder, and almost none of Shadow Shaman's spells can bypass spell immunity, except for Mass Serpent Ward.
* Bear in mind, however, that if Shadow Shaman gets a jump on Luna first, he will be able to use Hex to disable Luna and burst her down before she can use Black King Bar, Lucent Beam or Eclipse. In addition, Moon Glaives cannot bounce on Mass Serpent Wards at all.
Shadow Shaman
* A couple of nukers and disablers on the same lane can finish a squishy Luna efficiently despite a teammate's assistance: Sven + Shadow Shaman.
Medusa
* Should Luna choose to buy Manta Style, Medusa will be able to kill illusions from them with Split Shot and 
Mjollnir, which is a common item on Medusa.
* Mystic Snake allows Medusa to easily harass Luna and steal mana from her, preventing Luna from retaliating with Lucent Beam.
* Medusa can survive Eclipse thanks to Mana Shield, which can cause Luna to struggle greatly in bursting down Medusa and force her to buy Diffusal Blade and it's upgrade Disperser.
* Even with Black King Bar, Medusa's Stone Gaze will still be able to disable Luna, which could even discourage her from counter-initiating with Eclipse.
* For the same reasons, Medusa makes a very powerful ally for Luna when they are in the same team.
Additional:
* Should Luna choose to buy Manta Style, Medusa will be able to kill illusions from them with Split Shot and Mjollnir, which is a common item on Medusa.
* Mystic Snake allows Medusa to easily harass Luna and steal mana from her, preventing Luna from retaliating with Lucent Beam.
* Medusa can survive Eclipse thanks to Mana Shield, and since Luna is not a hero that often goes for Diffusal Blade, she will struggle greatly in bursting down Medusa.
* Even with Black King Bar, Medusa's Stone Gaze will still be able to disable Luna, which could even discourage her from counter-initiating with Eclipse.
* For the same reasons, Medusa makes a very powerful ally for Luna when they are in the same team.
Shadow Shaman
* Heroes with channeling spells because Shadow Fiend has nothing to cancel channeling outside of Requiem of Souls: Bane, Enigma, Pudge, Shadow Shaman, Dawnbreaker, Warlock, Crystal Maiden.
Shadow Shaman
* Heroes with silence and mana drain abilites, as Ancient Apparition relies entirely on his abilities: Invoker, Silencer, Nyx Assassin, Skywrath Mage, Shadow Shaman, Lion and etc.
Shadow Shaman
* Viper cannot interrupt heroes with powerful channeling abilities: Bane, Enigma, Shadow Shaman, Warlock
Shadow Shaman
* Heroes that can keep Marci for a long time in one place so she can't pursue her targets, like Bane, Lion, Shadow Shaman, Invoker, 
Disruptor and Kunkka.
Additional:
* Shadow Shaman can provide an excellent counter-initiation against her 
Rebound. His abilities can shut down any of her tower dive attempts in the laning phase.
* Shackles keeps Marci stunned for an extended time, wasting her ultimate. A combo with Mass Serpent Ward only makes things worse for her, as her armor is low.
Medusa
* Heroes with strong area-of-effect damaging and/or disabling abilities will be able to intercept Underlord and his team when they exit from Fiend's Gate: Luna's Aghanim's Scepter upgraded Eclipse, Dawnbreaker's Solar Guardian, Axe's Berserker's Call, Mars's Arena of Blood, Jakiro's Macropyre, 
Dual Breath and 
Ice Path, Naga Siren's 
Song of the Siren, Razor's Eye of the Storm and Plasma Field, Lina's 
Light Strike Array, Broodmother's 
Spinner's Snare from Aghanim's Scepter, Elder Titan's 
Earth Splitter and 
Echo Stomp, Alchemist's 
Unstable Concoction and 
Acid Spray, Queen of Pain's 
Sonic Wave, 
Dark Seer's 
Wall of Replica and 
Vacuum, Venomancer's 
Noxious Plague and 
Poison Nova from Aghanim's Scepter, Oracle's 
Fortune's End and 
Rain of Destiny from Aghanim's Shard, Bloodseeker's 
Blood Rite, Enigma's Black Hole and 
Midnight Pulse, Shadow Fiend's 
Requiem of Souls, Batrider's Aghanim's Scepter upgraded Flaming Lasso, 
Firefly, 
Flamebreak and 
Sticky Napalm, Ancient Apparition's 
Ice Blast, Sand King's 
Epicenter, 
Sand Storm and 
Burrowstrike, 
Gyrocopter's 
Call Down, 
Ember Spirit's 
Sleight of Fist, Death Prophet's 
Exorcism and 
Silence, 
Monkey King's 
Wukong's Command, Crystal Maiden's 
Freezing Field, 
Muerta's 
The Calling, Medusa's Stone Gaze, Zeus's 
Nimbus from Aghanim's Scepter. 
Dark Willow's 
Bramble Maze, 
Pangolier's 
Swashbuckle, Grimstroke's Soulbind, 
Ink Swell and 
Stroke of Fate, 
Earthshaker's 
Echo Slam and 
Fissure, Puck's 
Dream Coil and 
Waning Rift, 
Winter Wyvern's 
Winter's Curse, Magnus's Reverse Polarity.
Medusa
* Heroes that build Diffusal Blade or can fit it well into their item build will also make Medusa much less tanky: Riki, Naga Siren, Terrorblade, Juggernaut, Spectre, Slark.
Shadow Shaman
* All of Shadow Shaman's abilities totally ruin Terrorblade: Ether Shock destroys his illusions, Hex prevents him from using 
Sunder or Manta Style in bad situations, Shackles not only that prevent him from using Sunder, but he has no way to cancel it and Mass Serpent Ward can help Shadow Shaman push faster than Terrorblade even in 
Metamorphosis.
Additional:
* Ether Shock, Mass Serpent Wards summoned from both, Mass Serpent Ward and Aghanim's Shard upgraded Shackles can do great damage to both, Terrorblade and his illusions.
* Hex prevents Terrorblade from using Sunder or Manta Style in bad situations. Hex can also destroy one of his illusions.
* Shackles can damage Terrorblade and prevent him from using his abilities and items, whether to fight, survive, or dispel it in any way while also healing Shadow Shaman in process. In addition, Terrorblade has no solutions to cancel it. Aghanim's Shard upgraded Shackles can also summon four more Mass Serpent Wards to attack Terrorblade while he is disabled.
Medusa
* Heroes that build Diffusal Blade or can fit it well into their item build will also make Medusa much less tanky: Riki, Naga Siren, Terrorblade, Juggernaut, Spectre, Slark.
Medusa
* Medusa's Split Shot and Mystic Snake combined with Mjollnir, a common item for Medusa, will whittle down all of Naga Siren's illusions, including Naga Siren herself.
* Medusa's Stone Gaze can disable Naga Siren even for the duration of Song of the Siren and even if Naga Siren is spell immune, discouraging Naga Siren from even trying to use Song of the Siren to save herself or counter-initiate against Medusa.
Additional:
* Medusa's Split Shot and Mystic Snake combined with Mjollnir, a common item for Medusa, will whittle down all of Naga Siren's illusions, including Naga Siren herself.
* Medusa's Stone Gaze can disable Naga Siren even for the duration of Song of the Siren and even if Naga Siren is spell immune, discouraging Naga Siren from even trying to use Song of the Siren to save herself or counter-initiate against Medusa.
Medusa
* 
Burning Spear's damage over time can rapidly burn Medusa's mana and health alike.
* 
Inner Fire can slow and disarm Medusa and also allow Huskar to follow up with Life Break.
Shadow Shaman
* Mass Serpent Ward rips apart Huskar quickly due to his poor armor.
* As soon as Huskar jumps in, he will be vulnerable to Shadow Shaman's disables if he does not have Black King Bar.
Medusa
* Other heroes who has armor and slow debuffs won't allow Medusa to disengage from combat: Tidehunter, Bristleback, Slardar.
Medusa
* Medusa cares less than other heroes about armor reduction, since Mana Shield blocks 70% of all damage without taking armor/magic resistance into consideration. This makes 60% of your Corrosive Haze ineffective until Medusa's mana is drained.
Medusa
* Hard carries who just want to farm and be left alone will not appreciate Primal Beast, heroes such as Medusa, Drow Ranger...
Shadow Shaman
* Like above, supports with reliable stuns can be a massive problem and force Black King Bar in fights unideally, such as Shadow Shaman, Lion, Nyx Assassin.
Shadow Shaman
* With all 5 Meepos available, all of Shaman's wards will be disposed of very quickly.
* All of Shaman's disables are based around single target control, and he can at most only disable two Meepos, allowing the rest to easily lay waste to him, be it during the channel duration of Shackles or by using 
Earthbind.
Medusa
* Poof won't damage Medusa and she can use Stone Gaze to disable all of Meepo's clones.
* Mystic Snake will easily become the bane of Meepo early game.
Shadow Shaman
* Heroes with summons and illusions can find themselves easily bested by Lina, like Broodmother, Nature's Prophet, 
Chen, Terrorblade, Naga Siren, Visage, Wraith King, Lycan, Phantom Lancer, Shadow Shaman.
Medusa
* Heroes with a lot of burst damage, especially those who rely on casting spells: Lina, Zeus.
Shadow Shaman
* Due to their high attack speed, 
Summon Familiars will destroy Mass Serpent Wards quickly, granting Visage a massive amount of gold.
* Visage can use 
Stone Form of the Familiars to cancel Shackles. Aghanim's Shard upgraded Stone Form also allows Visage to use Stone Form himself to cancel Shackles while restoring his health.
* 
Grave Chill can make Shadow Shaman's bad movement speed and attack speed even worse.
* Visage is also a natural 
Bloodthorn wielder, which allows him to silence Shadow Shaman and make him more vulnerable to damage.
Additional:
* Due to their high attack speed, Visage's Summon Familiars will destroy Mass Serpent Ward quickly, granting Visage massive amount of gold.
Medusa
* Visage's familiars are easy targets to Split Shot.
* Mana Shield will resist Soul Assumption instances without effort.
Shadow Shaman
* Riki is known for being a successful support killer, something Shadow Shaman is very vulnerable to.
Smoke Screen is particularly devastating to Shadow Shaman. With neither his various disables nor a solid health pool Shadow Shaman is usually dead. This forces Shadow Shaman to buy a 
Force Staff if he finds himself in this scenario and buy 
Sentry Wards if you have the money.
*
Medusa
* With
Smoke Screen, Riki will silence and catch Medusa in a surprise with high miss chance flushing her from positions easily in team fights.
Cloak and Dagger, even through Mana Shield.
* He can deal a huge amount of damage through